Cogeneration cabins are made to accommodate the engines of a cogeneration system. They are made with weight-bearing metal structures, soundproof and sound absorbing panelling, and splitter silencers that, with the aid of forced ventilation, allow a large flow of air to cool the engines. The cabins can also be made to house plant rooms such as pump rooms, electrical panels and substations. Cabins made and customised to customer requirements can be designed to support roof systems.